Some known binder mechanisms include support rails positioned within a binder housing such that the support rails may be secured in two stable positions. The first position may correspond to a position in which the binder mechanism is in a closed position and the second position may correspond to a position in which the binder mechanism is in an open position. The binder housing may be elastic and/or spring-like to fix and/or secure half rings connected to the respective support rails in the open and/or closed positions. Entrainers and/or joint elements may be positioned between inner longitudinal edges of the support rails to ensure that the support rails abut one another obtusely at their inner longitudinal edges. The outer edges of the support rails may be resiliently held such that the support rails function as a toggle lever.
Some known binder mechanisms may also include a locking mechanism that includes one or more locking elements that secure corresponding half rings in the closed position. Securing the binder mechanism in the closed position may be brought about solely by blocking the support rails. As such, a limited amount of force urges and/or maintains the free ends of the half rings together (i.e., the ends not connected to the support rails). Some known binder mechanisms such as that described in EP 1 189 764 BZ, include a locking rod that may be actuated independently from the support rails. Locking elements that act against the support rails may be coupled to and/or associated with the locking rod.
U.S. Pat. No. 7,600,939 describes that the free ends of the half rings may include interlocking locking elements. The locking elements may interlock in the closed position, thereby preventing the pivoting of the support rails about a pivot axis. When opening such binder mechanisms, one of the support rails may be moved relative to the other support rail along a movement path to initiate and/or trigger the unlocking of the locking elements by moving the half rings from an overlapping position to an exposed position.